The envelope was addressed to Mike Seay, but the second line read "Daughter Killed in Car Crash."

Seay's 17-year-old daughter, Ashley, was one of two teens killed in a crash last April when their SUV veered off the road and slammed into a tree in Antioch.

Seay says he thinks about his daughter "10,000 times a day," and was shocked to see the insensitive letter.

"Why would they have that type of information? Why would they need that?" Seay told NBC 5. "What purpose does it serve anybody to know that? And how much other types of other information do they have if they have that on me, or anyone else? And how do they use that, what do they use that for?"

Seay asked his Facebook friends how he should handle it, and eventually decided to contact the OfficeMax call center.

"The manager told her that it was impossible, that this can't be happening," Seay said.

NBC 5 reached out to Naperville-based OfficeMax, who blamed it on a third-party mailing list provider. The corporate affairs office released the following statement:

"We are deeply sorry that Mr. Seay and his family received this mailing from us, and we are reaching out to Mr. Seay to convey our sincerest apologies on this unfortunate matter. This mailing is a result of a mailing list rented through a third-party provider. We have reached out to the third-party mailing list provider to research what happened. Based on a preliminary investigation today we believe this to be an inadvertent error; and we are continuing the investigation. -- " -- Nicole Miller